Most surprising/disappointing players of the 2018 MLB season

Most surprising catcher: Elias Diaz, Pirates

2018 was a dud for catchers, but the Pirates found a potential building block with Diaz. Sharing time with Francisco Cervelli, Diaz is hitting .286-9-30 in 255 plate appearances and playing terrific defense. His .790 OPS is a significant improvement over last season and could spur the Pirates to trade Cervelli in the offseason.